Abstract Introduction The management of complex anal fistulae remains a topical surgical problem. The choice and success of surgical management are based on the balance between healing and continence. Although porcine dermal collagen (Permacol Collagen Paste [PCP]- Covidien plc, Gosport, Hampshire, UK) represents a new generation of non-solid biomaterials, its results in anal fistulae are mixed. Methods A multicenter observational retrospective analysis of consecutive patients with cryptoglandular anal fistula treated in four colorectal surgery units was performed between 2015 and 2020. Clinical cure of the fistula was the main outcome measure. Adverse events and alterations in anal continence were secondary outcomes. Results The study included 119 patients (87 males, 71.1%), with a mean age of 53 years (IR 44-65). Most patients had complex (80.6%) and recurrent (91.6%) fistulae. With the first PCP treatment, the overall cure rate was 41.2% (49 patients) and 45.4% with the second treatment (5 out of 17 patients). The mean follow-up period was 17 months (IR 5-25). Healing was not affected by the location and type of fistula, the existence or not of a cavity, the number of tracts, or the administration of prophylactic antibiotics. After the PCP treatment, no patient in the series had worsening of continence. Morbidity affected 22.7% of the patients (27), with postoperative abscesses being the most frequent adverse event. There were no statistical differences between the four hospitals studied. Conclusions Permacol collagen paste is a safe and easily reproducible therapy for complicated anal fistulae that has moderate efficacy. The overall success rate is slightly over 40%, with no detriment to fecal continence.

ABSTRACT Purpose: the aim of this study was to compare overall and disease-free survival among patients with colorectal cancer detected via a screening program as compared to those with symptomatic cancer. Material and methods: patients diagnosed via colonoscopy (screening group) and those with clinical symptoms (non-screening) were identified from 1995 to 2014. Demographic, clinical, surgical and pathologic variables were recorded. Stage I, II and III cancers were included. Overall and disease-free survival were calculated at five and ten years after tumor resection and survival was calculated by matching both groups for cancers at stage I, II and III. Results: two hundred and fifty patients were identified as a result of screening procedures and 1,330 patients presented with symptomatic cancers. There were no significant differences in the baseline characteristics between the two groups. Pathologic stage, degree of differentiation, perineural invasion and lymphovascular invasion were lower in the screening group (p < 0.01). Overall and disease-free survival at five and ten years were higher in the screening group (p < 0.01). However, when the subjects were matched for pathologic stage, significant differences were found between the two groups with regard to stage I and III tumors. Disease-free survival in stage III at five years (79.1 vs 61.7%; p < 0.001) and ten years (79.1% vs 58.5%; p < 0.001) were significantly higher in the screening group. Conclusions: patients with stage I and III tumors that were diagnosed via a screening program have a higher overall and disease-free survival at five and ten years.

ABSTRACT Purpose: The objective of the study was to analyze the clinico-pathological differences and the oncologic outcomes between right and left-sided colon cancer. Patients and methods: The patients cohort was identified from a prospective register of colon cancer, 950 patients underwent surgery (stages I, II and III), of which 431 had right-sided colon cancer and 519 had left-sided colon cancer. Results: More laparoscopic resections were performed (101 vs 191; p < 0.001) and operating times were longer (146 min vs 165 min; p < 0.001) in the left-sided colon group. Patients with right-sided colon cancer more frequently received transfusions (18.8% vs 11.3%; p < 0.001) and experienced a greater number of complications (28.5% vs 20.9%, p = 0.004), although severity and operative mortality were similar in both groups (1.2% vs 0.2%). Mucinous adenocarcinomas and undifferentiated tumors were more frequent in the right-sided group (12% vs 6.5%; p < 0.001). Early stage was predominant in the left-sided colon tumors (28.2% vs 34.5%, p = 0.02). There were no differences in disease-free survival (DFS) in stages I and II after a median follow-up of 103 months. However, a greater survival at five and ten years in left-sided, stage III tumors was observed, with a trend towards statistical significance (p = 0.06). No differences were found with regard to the patterns of recurrence. Conclusions: Right-sided colon cancer exhibits phenotypical differences with regard to left-sided colon cancer. In stage III disease, left-sided colon cancer has a greater survival with a trend towards statistical significance. Overall, tumor location is a variable that should be taken into consideration in clinical studies of colon cancer.

Background: The standard treatment for locally advanced cancer of the rectum (LACR) and selective cases of stage IV disease is preoperative chemoradiotherapy (CRT) followed by total mesorectal excision (TME). Despite reductions in local recurrence, disease-free survival (DSF) has remained stable in recent years. Objective: The objective of this study is to analyze patterns of recurrence, long-term survival and prognostic factors in a program of neoadjuvant CRT and surgery in LACR. Methods: Between January 1992 and December 2011, 446 patients with LACR and 54 patients (with single metastases) were treated with pre-operative long course CRT and surgery. Three hundred forty four (66.8%) anterior resections of the rectum and 123 (24.6%) abdomino-perineal resections were performed. Results: With a mean follow-up of 70.06 months, local recurrence was 4.8% and distant recurrence 25.5%. No differences were found in the histopathologic prognostic factors across the three groups studied depending on distance (cm) from the anal margin. Involvement of the circumferential resection margin (CRM+) was significantly greater in tumors in the distal third of the rectum (8.5%; p = 0.04). 67 patients (13.4%) showed a complete pathologic response. DSF at 5 and 10 years was significantly lower in patients with tumors affecting the distal third as compared to the middle third of the rectum (61.9% vs. 57.7%; p = 0.04). Tumors at this distal location resulted in a significantly higher incidence of lung metastases (p = 0.016).

Antecedentes: el tratamiento del cáncer de recto localmente avanzado (CRLA) y de casos selectivos de estadio IV es la quimio-radioterapia (QRT) preoperatoria seguida de la extirpación completa del meso-recto (ETM). A pesar de la reducción en la recurrencia local, la supervivencia libre de enfermedad (SLE) permanece estable en los últimos años. Objetivo: el objetivo de este trabajo es analizar el patrón de recidiva, supervivencia a largo plazo y los factores pronósticos en un programa de QRT neoadyuvante y cirugía en el CRLA. Métodos: ent re enero de 1992 y diciembre de 2011, 446 pacientes con CRLA y 54 pacientes (con metástasis únicas) fueron tratados con QRT preoperatoria de curso largo y cirugía. Se realizaron 344 (68,8%) resecciones anteriores de recto y 123 (24,6%) amputaciones abdominoperineales. Resultados: con una mediana de seguimiento de 70,06 meses, la recurrencia local fue del 4,8% y a distancia del 25,5%. No se encontraron diferencias en los factores pronósticos histopatológicos entre los tres grupos estudiados dependiendo de la distancia (cm) al margen anal. La afectación del margen circunferencial (MCR+) fue significativamente mayor en el tercio distal (8,5%; p = 0,04). Sesenta y siete pacientes (13,4%) mostraron una respuesta patológica completa. La supervivencia libre de enfermedad a los 5 y 10 años fue significativamente menor en los tumores del tercio distal del recto que en los del tercio medio (61,9% y 57,7%; p = 0,04). En dicha localización se produjo una incidencia significativamente mayor de metástasis pulmonares (p = 0,016).

Liver regeneration (LR) is one of the most amazing tissue injury response. Given its therapeutic significance has been deeply studied in the last decades. LR is an extraordinary complex process, strictly regulated, which accomplishes the characteristics of the most evolutionary biologic systems (robustness) and explains the difficulties of reshaping it with therapeutic goals. TH reproduces the physiological tissue damage response pattern, with a first phase of priming of the hepatocytes -cell-cycle transition G0-G1-, and a second phase of proliferation -cell-cycle S/M phases- which ends with the liver mass recovering. This process has been related with the tissue injury response regulators as: complement system, platelets, inflammatory cytokines (TNF-α, IL-1β, IL-6), growth factors (HGF, EGF, VGF) and anti-inflammatory factors (IL-10, TGF-β). Given its complexity and strict regulation, illustrates the unique alternative to liver failure is liver transplantation. The recent induced pluripotential cells (iPS) description and the mesenchymal stem cell (CD133+) plastic capability have aroused new prospects in the cellular therapy field. Those works have assured the cooperation between mesenchymal and epithelial cells. Herein, we review the physiologic mechanisms of liver regeneration.

La regeneración hepática (RH) representa una de las formas más extraordinarias de respuesta al daño tisular. Debido a sus implicaciones terapéuticas, ha sido motivo de un interés extraordinario en las últimas décadas. La RH es un proceso muy complejo y estrictamente regulado que cumple las características de los sistemas biológicos más evolucionados (robustness) y que explica la dificultad de interferir en ella con usos terapéuticos. La RH reproduce el modelo fisiológico de respuesta al daño con una fase primera de preparación o "cebado" de los hepatocitos -transición G0-G1 del ciclo celular- y una fase ulterior de proliferación -fases S/M del ciclo- que termina con la recuperación de la masa hepática. Dicho proceso se ha relacionado con los mediadores de la respuesta biológica al daño tisular: hormonas, sistema del complemento, plaquetas, citocinas proinflamatorias (TNF-α, IL-1β, IL-6), factores de crecimiento (HGF, EGF, VGF, etc.) y factores antiinflamatorios (Il-10, TGF-β). Debido a su complejidad y a su estricta regulación, se explica que todavía hoy la única alternativa a la insuficiencia hepática sea el trasplante hepático. La identificación reciente de las células pluripotenciales inducidas (iPS) y la capacidad plástica de las células madre mesenquimales (CD133+) ha suscitado nuevas expectativas a la terapia celular regenerativa. Dichos trabajos han confirmado la cooperación entre las células mesenquimales y epiteliales. En el presente trabajo se describen los mecanismos fisiológicos de la regeneración hepática.

Backgrounds: the treatment of a perforated giant duodenal ulcer (GUDs) represents a formidable surgical challenge regarding the duodenal wall defect repair in severe peritonitis setting. A high incidence of dehiscence and hospital mortality (15-40%- has been reported with the majority of the techniques). We report a case of GUDs perforation successfully treated with a subtotal gastrectomy and a gastric patch with the remnant antrum, for repairing the duodenal defect. Case report: a 63-years-old man with antecedents of peptic ulcer disease presents a large duodenal ulcer perforation with 48 hrs delay and associated with severe peritonitis and a retroperitoneal collection. A subtotal gastrectomy with Billroth II reconstruction and reconstruction of the duodenal defect with a patch of the remnant antrum was carried out. The patient was discharged at 17th postoperative day with good tolerance. Discussion: the duodenal defect repair with a patch of the remant antrum, represents a valid alternative in similar circumstances. To our knowledge, it appears to be the first clinical description of this technique.

Antecedentes: el tratamiento de un ulcus duodenal gigante (UDG; > 2 cm) perforado entraña una gran dificultad técnica, por la reparación del gran defecto duodenal; y por la peritonitis sobreañadida. Todas las técnicas descritas se asocian con un índice elevado de dehiscencias y una mortalidad del 15-40%. Describimos por primera vez el caso de un UDG perforado, tratado mediante una gastrectomía subtotal y con una plastia del antro gástrico remanente. Caso clínico: varón de 63 años que se interviene de un UDG perforado en la 2ª porción duodenal asociado con peritonitis severa y disección de la gotiera parieto-cólica derecha retroperitoneo. Se realiza gastrectomía tipo Bilroth II y reparación del defecto duodenal mediante una plastia con la pared del antro gástrico remanente. El paciente fue dado de alta a los 17 días. Discusión: la reparación del defecto duodenal con una plastia del antro gástrico, puede ser una opción muy valiosa en situaciones similares a la descrita. En nuestro conocimiento, se trata de la primera descripción clínica de esta técnica.